1. Field of the Invention
The present invention relates generally to data storage using media and more particularly to increased data storage using magneto-optical data media.
2. Background Art
Information storage technology and the storage capacity available therefrom has historically been limited by a number of factors. A typical prior art Winchester magnetic storage system includes a magnetic head that has a slider element and a magnetic read/write element and is coupled to a rotary actuator magnet and coil assembly by a suspension and actuator arm so as to be positioned over a surface of a spinning magnetic disk. In operation, lift forces are generated by aerodynamic interactions between the magnetic head and the spinning magnetic disk. The lift forces are opposed by equal and opposite spring forces applied by the suspension such that a predetermined flying height is maintained over a full radial stroke of the rotary actuator assembly above the surface of the spinning magnetic disk.
Flying head designs have been proposed for use with other storage technologies, including magneto-optical (MO) storage technology. Magneto-optical information access requires the use of polarized laser light for reading and writing information on an MO disk. In the case of reading information, MO technology makes use of a magneto-optical effect ("Kerr" effect) to detect a modulation of polarization rotation imposed on the linearly polarized incident laser beam by the recorded domain marks in the recording layer. The polarization rotation (representing the information stored at recorded marks or in the edges of the recorded marks) is embodied in a reflection of the linearly polarized laser beam and is converted by optics and electronics for readout.
Increased storage capacity with storage drives up to present has been addressed through improvements in the ability to store information on the particular storage disk with an increased areal density, e.g., decreasing the size of the optical spot formed by the laser light in a magneto-optical system. Until recently, these prior art approaches have been adequate for increasing storage capacity and, therefore, other approaches have not been fully explored.
One factor that limits disk drives is the inability to fully utilize an entire disk surface area for information storage. This limitation is partly due to a "ski jump" that is formed during an injection molding process of the prior art disks. Because a surface area of an outer radial region of the prior art disk containing the ski jump is not sufficiently flat, an air bearing suitable for sustaining a flying condition is not maintainable for flying a head over this outer radial region. Also, the bulk properties of the outer radial region in the area near the ski jump may create high stress in the region such that passage of light through the magneto-optical layers for reading and writing of information in the region is adversely affected.
What is needed, therefore, is an apparatus and method that improves upon prior art access to, and storage of, information on storage media.